Valve plate mounting for a cylinder and multi-piston type pump



v JanQB, 1967 fr. H.Tr-ICMVHDSCDNv V3,295,460

' VALVE PLATEA MOUNTING` FOR A CYLINDER AND MULTE-PESTON TYPE PUMPA ,K E a i FI/6. 1 f

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-i num INVENTOR TOM H; THOMPSON ATTORNEYS #Www Jan. 3, 1967 T. H. THOMPSON 3,295,460

' VALVE PLATE MOUNTING FOR A CYLINDER AND MULTI-'IsToN TYPE PUMP 4 Filed Dec. 2i, 1964. s sheets-sheet 2 INVENTOR.

y TOM H. THOMPSON ATTORNEYS Jan. 3, 1967 y -T. l-i.l THOMPSON 3,295,460

VALVE PLATE MOUNTING FOR A CYLINDER AND'MULTI-PISTON TYPE PUMP Filed Dec. 2l, 1964 Y v 5 Sheets-Sheet 5 FIG.l V5

l INVENTOR I TOM H. THOMPSON AT TORNE YS United States Patent O 3,295,466 VALVE PLATE MOUNTING FOR A CYLINDER AND MULTI-PISTGN TYPE PUMP Tom H. Thompson, Carrier 6, Ponce Park, Daytona Beach, Fla. 32019 Filed Dec. 21, 1964, Ser. No. 419,670 14 Claims. (Cl. 1133-162) This invention relates generally to lluid pressure energy translating devices of the cylinder and multi-piston type wherein the device comprises a cylinder block or barrel carrying a plurality of pistons circularly arranged concentrcally about the barrel axis and reciprocably received in bores or cylinders in the barrel for reciprocation parallel to the barrel axis. Such devices comprise an inclined or inclinable wobble or cam plate dispo-sed coaxially of the barrel axis and operatively connected to the pistons, whereby the pistons will be reciprocated in the barrel in response to relative rotation between cam plate and the barrel.

More particularly, this invention relates to means for mounting a valve plate in engagement with one end of the cylinder barrel. Such a valve plate conventionally has a pair of grooves extending arcuately 4about the axis of the barrel and on opposite sides of the barrel axis. The grooves are connected respectively, to fluid inlet and outlet conduits and registerable with ports or passages in the next adjacent end of the barrel communicating with or forming a part of the piston receiving cylinders, whereby liuid will be alternately introduced and discharged from each cylinder during relative rotation between the cam plate and barrel.

In a device of the type described it is very desirable that the valve plate contact the next adjacent end of the barrel entirely about the Ibarrel axis, Vor in other words, that there be no angularity between the general planes of the next adjacent contacting surfaces of the barrel and valve plate as might occur if the valve plate and barrel axis were not coincident. It will be apparent that extreme care must be taken during manufacture ofthe barrel, valve plate and the means mounting the same to assure the close iitting relationship desired between the contacting surfaces of the valve plate and barrel, and such extreme tolerances necessarily increases the cost of manufacture.

Additionally, it is desirable to preload the valve plate in the direction of the barrel to assure firm contact between the valve plate and barrel so as to, at least, minimize leakage 'between the next adjacent surfaces of the barrel and valve plate. Accordingly, it is an object of the present invention to provide, in a fluid pressure energy translating device of the type described, novel and improved means for mounting a valve plate in operative relationship with one end of the cylinder 'barrel wherein the valve plate is mounted for resiliently restrained limited universal tilting movement about the axis of the barrel and the valve plate is urged into firm engagement with barrel.

In a device of the type described wherein there is relative rotation between the valve plate and barrel, high static loading on the barrel and valve plate in the direction of the axis thereof results in friction loading between the contacting surfaces of the valve plate and barrel which may substantially increase the starting torque of the device. Accordingly, included within the objects of the present invention is the provision of novel and improved means for mounting the valve plate in operative position relative to the barrel which will maintain the starting torque of the device at an `acceptable level even when there is a high static load on the barrel and valve plate.

The novel features which are believed to ybe characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as ICC to its organization and method of operation, together with further objects and advantages thereof, may best be understood by references to the following description taken in connection with the accompanying drawings,`in which:

FIGURE l is a side view, partially cut away and partially in section, of a variable displacement hydraulic pump incorporating the present invention;

FIGURE 2 is a cross-sectional view substantially along the line 2-2 of FIGURE l;

FIGURE 3 is a cross-sectional view substantially along the lines 3 3 of FIGURE 2;

FIGURE 4 is an elevational view of an alternative embodiment of the invention; and

FIGURE 5 is a cross-sectional view substantially along the lines 5-5 of FIGURE 4.

With reference to the drawings the invention is shown in connection with a hydraulic pump comprising a housing I0 at one end of which is disposed a rotatable pulley 12 adapted to be driven -by a V-belt. The pulley is lixed to a drive shaft 14 extending coaxially of and journaled on the housing. One end of the shaft is journaled by a bearing as at 16, carried by an end wall 18 of the housing. Disposed within the housing are a pair of axially aligned and spaced cylinder barrels =or rotors 2li which are arranged coaxially over the drive shaft 14 and are xed for rotation with the shaft such as by a Woodruif 22. Each of the ybarrels 20 has a plurality of cylinders 24 circularly arranged conceutrically of the axis of the barrel. Each of the cylinders 24 opens outwardly of the end of lrespective barrel which is'next adjacent to and faced oppositely the other barrel 20. Each of the cylinders terminate intermediate the ends of the respective barrel in a fluid passage 25 which is of substantially lesser diameter than the cylinder yand is arranged coaxially thereof` Each passage 25 extends from the inner end of the respective cylinder through a wear plate 26 forming one end of the barrel. One end of a double acting piston 28 is received in each of the cylinders 24 for `reciprocation therein. Each of the pistons has a portion intermediate its ends which is polygonal in cross section thus being provided With a plurality of flats, as at 30, extending in parallel radially outwardly spaced relation to the longitudinal axis of lthe piston. One of the ats 30 on each of the pistons is in engagement with one of the flats 30 on each of the pistons is in engagement with one of the flats 32 of a spacer sleeve 31 arranged coaxially over the shaft 14. In this manner the axis of each of the pistons 28 is fixed relative to the shaft 14 and barrels 20 so as to assure rotation of the pistons with the shaft while permitting reciprocation of the pistons longitudinally of the shaft 14 and axially of the respective cylinders.

Disposed about the drive shaft 14 is a generally cylinderical frame 36 which is suitably mounted, by means not shown, for tilting movement about an axis extending at right angles to the longitudinal axis of the frame and the axis of the shaft 14. Rotatably supported on the frame 36 for movement about the longitudinal axis of the frame is a cam ring 37 having a generally annular projection 3S disposed coaxially about and extending toward the shaft 14.` The annular portion 38 is engageable in a slot in a ball 40 carried by each of the inter mediate portions of each piston 2S, thus providing a ball and socket driving connection between each of the pistons, and the cam 37. It will be apparent to those skilled in the art, inasmuch as the pivotal axis of the frame 36 is fixed relative to the housing, rotation of the shaft 14, and corresponding rotation of the barrel Ztl, will result in reciprocation of the pistons 28 in their respective cylinders with the stroke of the pistons being determined by the amount of inclination of the frame 36 about its pivotal axis and relative to the axis of the shaft 14.

As is well known, in devices of this type, as the pistons are reciprocated fluid will be drawn into each cylinder during a portion of its travel about the axis of the shaft 14 and will be exhausted from the cylinder during another portion of its travel about the axis of the shaft 14. In this connection, a valve plate 34 is disposed in engagement with the end of each barrel opposite the pistons 28. In the interest of brevity only one valve plate 34 and associated structure is shown, it being understood that the valve plate and associated structures relating to the leftward barrel of FIG. 1 is the same as that of the rightward barrel 20. As shown in FIGS. 2 and 3, the valve plate is provided with a pair of arcuate grooves 36, 38 which are .adapted to register with the outer ends of the passages in the barrel as the barrel is rotated. The valve plate is further provided with tluid passages 46, 42 which extend through the valve plate. The passages 40, 42 at one end respectively communicate with the arcuate passages 36, 38. In the specific embodiment shown, the valve plate is generally annular and is disposed coaxially over the shaft 14.

In accordance with the invention, the valve plate is supported in operative relationship to the barrel by means of an annular member or ring 44 fabricated from an elastomeric material. The plate 34 and ring 44 are coaxially arranged with the ring 44 disposed on the side of the plate opposite the barrel 20. The next adjacent surfaces of the ring and valve plate are xed relative to each other such as by bonding the ring to the valve plate by a suitable adhesive. The surface of the ring 44 opposite the surface ythereof which is bonded to the valve plate is fixed relative to the housing such as by adhesive bonding of the ring to 4an annular metal ring 46 which is disposed between the elastomeric ring 44 and the housing end wall 18 and which is fixed to the end wall 18. With reference to FIG. 3, the elastomeric ring 44 is provided with a pair of passagesl 48, 50 extending from one side to the other of the ring in respective alignment with the passages 40, 42 in thevalve plate. The support ring 46 is likewise provided with through passages 52, 58 extending from one side to the other of the ring -and in alignment respectively with the passages 48 and 50 in the 1elastomeric ring 44. The passages 52, 54 in the support ring are in registry with passages 56, 58 in the end wall 18 of the housing which are adapted to be connected respectively to inlet and discharge luid lines externally of the pump. Accordingly, in the specific embodiment shown, as the barrel 20 is rotated in a counterclockwise direction as viewed in FIG. 2, Huid will be drawn into the cylinders 24 through the passages 25, groove 36 and passages 40, 48, 52 and 56. Correspondingly, fluid will be subsequently discharged from the cylinders 24 through the passages 25, groove 38 and passages 42, 50, 54 and 58 as the barrel is continued to be rotatedV in a counterclockwise direction as viewed in FIG. 2.

In order to improve the sealing around the next adjacent ends of the aligned passages 40',Y 4S and 42, Si) the valve plate 34 is provided with an annular groove surrounding each of the openings 40, 42 in radially outwardly spaced relation. An O-ring 60 is received in each of the grooves. Similar grooves may be provided in the oppositely facing surface of the elastomeric ring 44.

As will be apparent from the consideration of the drawings, the support ring 46 has an outer diameter which is greater than the outer diameter of the elastomeric ring 44 and an inner diameter which is less than the inner diameter of the ring 44. The support ring 46 is mounted on the end wall 18 of the housing by a plurality of screws 62 extending through the radially outwardly extending portion of the ring 46 and by a plurality of screws 64 extending through the radially inwardly extending portion of the ring 46. As will be seen in FIG. 2, the screws 62 are angular offset about the axis of the support ring 46 relative to the screws 64, whereby the screws 64 lie midway between the screws 62. This manner of mounting the ring 46 improves the fluid sealing between the contacting surfaces of the ring 46 and end wall 14.

As has been noted, the ring 44 isfabricated from an elastomeric material. In actual practice Buna-N has proved to be a satisfactory material, however, other elastomeric or resilient materials could be used where suit able for the purposes intended. The elastomeric ring 44 is of sul'licient depth or thickness as measured axially of the ring, to permit universal tilting movement of the valve plate 34 about the axis of the valve plate and generally about the axis of the shaft 14. Also, the elas-` tomeric ring 44 is of sufficient thickness that when the ring is under substantial axial compression the yuniversal tilting support of the valve plate will still be provided.`

It will be observed from FIG. 1 that the spacer sleeve 44 intermediate the barrels 20 engages the next adjacent ends of the barrels. Further, the distance between the ends of the spacer sleeve and the next adjacent end walls of the housing together with the relative dimensions ofV valve plate and the mounting means therefor as measured generally axially the shaft 14 are such that when the pump is assembled the elastomeric ring 44 will be under substantial axial compression in order to provide a good uid seal between the next adjacent contacting surfaces of the valve plate and barrel. Where the longitudinal axes of the barrel and the next adjacent valve plate are not coincident, rotation of the barrel relative to the valve plate could cause uneven wear or leakage. However, in`

the valve plate mounting means of this invention the universal tilting movement permitted the valve plate by the elastomeric ring 44 assures that the v alve plate will always be in axial alignment with the barrel and that the next adjacent surfaces thereof will be in contact evenly about the axis of the barrel.

Where there is a substantial preloading of the elastomeric ring 44 when the pump is assembled or where the input fluid to the device is pressurized, there may be high static forces acting on the contacting surfaces of the valve plate and `barrel tending to resist initial rotation of the barrel. This would result in a starting torque which `in some cases may be undesirably high. In accordance with the invention the elastomeric ring 44 is made suiiciently thick that substantial torsional movement may occur between the opposite ends or faces thereof. Thus, where a suliciently high starting friction is present between the contacting surfaces of'the valve plate and barrel, the

valve plate will tend to move with the barrel -about the axis of the shaft 14. As the ring 44 is fabricated from rubber or rubber-like material, this placing of the ring in torsion will result in the ring -tending to reduce slightly in thickness, thereby reducing the friction loading between the plate and 'barrel and permitting the barrel to begin to rotate with less starting torque than would otherwise be, the case. By Way of example, in a practical embodiment of the invention, the elastomeric ring `44 had an outer diameter of 2.25 inches, an inner diameter of 1.00 inch extending less than 180 about the axis of the valve plate and disposed on opposite sides of the valve plate axis. An inlet passage and an outlet passage 142 extend through the valve plate from one side to the other in respective communication at one end with the distribution grooves 136, 138. The valve plate is adapted to be supported on a housing end Wall or the like, as in the case of Y the embodiment of FIGS. 1-3, by means ineiuding an annular flat support member or ring 144. The support ring 144 is generally similar in construction to the ring 44 previously described, having an outer diameter and an inner diameter substantially larger than the corresponding dimensions of the valve plate 134 and having outer and inner openings 162 and 164, respectively, in which are receivable bolts or screws such as at 62 or 64 in FIG. 2. The bolt receiving openings 162 and 164 are offset angularly and between each other about the axis of the ring 144 for the same reasons as the corresponding openings in the embodiment of FIGS. 1-3. Also the ring 144 has a pair of uid passages 152, 154 extending through the ring for one side to the other in respective alignment with the passages 140, 142 in the valve plate. The passages 152, 154 are adapted to be connected to inlet and outlet passages (not shown) similar to those at 155, 158 in FIG. 3.

In accordance with this aspect of the invention, the valve plate 134 is supported on the ring 144 by a plurality of resiliently extensible and compressible members which in the specific embodiment shown are metal bellows '74?. The bellows 7() are circularly larranged equiangularly about and concentrically of the valve plate axis and are disposed between the valve plate and support ring with their axis extending parallel to the axis of the valve plate. The opposite ends of each bellows are fixed, as by welding, to the valve plate 134 and support ring 144, respectively. Accordingly, it will be appreciated that the valve plate is thus mounted for resiliently restrained limited movement about the valve plate axis and for resiliently restrained limited universal tilting movement relative to Vthe axis of the valve plate in order to provide the advantages and operational features attributable to such a mounting if the valve plate in connection with the embodiment of FIGS. l-3. Also, the laxial resilience of the bellows 7i) permits the valve plate 134 to be axially preloaded in the same manner and for the same purpose as the valve plate 34 previously described.

In accordance with another aspect of the invention, two of the bellows 7i) are in respective alignment with the passages 1413, 142 in the valve plate and these bellows are open at each end. The ends of these bellows are sealed to the valve plate 134 and ring 144 yabout the passages 146, 142 and 152, 154 in fluid tight relation. Thus the interior of these bellows provide a duid flow path between the next adjacent ends of the passages 149, 152 and 142, 154. While it is necessary that two bellows 7) be provided, the total number is generally a matter of choice, although it is preferable to provide at least three bellows.

inasmuch as the function and advantages of the embodiment of FIGS. 4 and 5 are essentially the same as those of the embodiment of FiGS. l-3, no further description thereof is required.

Accordingly, it will be seen that there has been provided in a fluid pressure energy translating device of the general type described a novel and improved means for supporting a valve plate wherein the valve plate is mounted for limited resiliently restrained movement about the axis of the barrel and for limited universal tilting movement relative to the barrel axis and with the support means 4being resiliently deformable generally axially of the barrel wherein the support means may serve as the means for preloading the contacting surfaces of the valve plate and barrel to reduce leakage therebetween.

While only certain preferred embodiments of this invention have 4been shown and described by way of illustration, many modifications will occur to those skilled in the art` and it is, therefore, desired that it be understood that v it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of this invention.

I claim:

1. In a fluid pressure energy translating device of the type having a rotatable cylinder barrel, a plurality of reciprocable pistons received in the cylinders of the barrel, and means providing a plurality of fluid passages respectively associated with the cylinders of the barrel and opening outwardly vat one end of the barrel; a valve plate having uid passages which communicate with the passages in said one end of the barrel, said valve plate being arranged coaxially of the barrel and being engaged with said one end of the barrel, and means mounting said valve plate for Iresiliently restrained limited movement about the rotational axis of the barrel and for urging the valve plate toward the barrel.

2. In a fluid pressure energy translating device of the type ha'ving a cylinder barrel, ya plurality of reciprocable pistons received in the cylinders of the barrel, and a plurality of fluid passages in the barrel communicating with the cylinders thereof and opening outwardly of one end of the barrel; a valve plate having fluid passages which communicate with the passages in the barrel at said one end of the barrel, said valve plate being arranged coaxially of the Ibarrel and being engaged with lsaid one end of the barrel, and `means mounting said valve for resiliently restrained limited universal tilting movement .relative to the laxis of the barrel and for urging the valve plate toward one end of the barrel.

3. In a fluid pressure energy translating device of the type having a rotatable cylinder barrel, a plurality of pistons respectively received in the cylinders of the barrel, and a plurality of fluid passages in the barrel respectively associated with said cylinders and opening outwardly of one end of the barrel; a valve plate having fluid passages communicating with the uid passages in the barrel, and means supporting said valve plate in engagement with said one end of the barrel and mounting the valve plate for resiliently restrained limited movement about the rotational of the barrel and for movement axially away from said one end of the barrel in response to movement of the valve plate angularly about said rotational axis, said means supporting said valve plate further mounting said valve plate for limited universal tilting movement relative to said rotational axis and for urging said valve plate toward said one end of the barrel.

4. In a duid pressure energy translating device of the type having a cylinder barrel, a plurality of reciprocable pistons respectively received in the cylinders of the barrel, and a plurality of fluid passages in the barrel communieating with the cylinders thereof and opening outwardly at one end of the barrel; a valve plate having opposite sides one of which is in next adjacent oppositely facing Vrelation to said one end of the barrel, said valve plate having fiuid passages communicating with the passages in said barrel, and resiliently deformable means xed relative to the other side of said valve plate and supporting the same in operative position relative to said one end of the barrel, said deformable means urging said valve plate into engagement with said one end of the barrel and mounting said valve plate for limited resiliently restrained tilting movement relative to the rotational axis of the barrel, said deformable means having iluid passages communicating with said uid passages in said valve plate.

5. In a fluid pressure energy translating device of the type having a housing, a cylinder barrel, a plurality of pistons lreciprocably received in the cylinders of the barrel and a plurality of fluid passages in the barrel respectively yassociated with said cylinders and opening outwardly at one end of the barrel; a valve plate next adjacent said one end of the barrel and having fluid passages communicating with the iluid passages in the barrel, and means supporting said valve plate in engagement with and in operative relation to said one end of the 'barrel including a member of .resiliently deformable non-metallic material extending about the axis of the barrel, means supporting the valve plate on said deformable member, and

means spaced from said means supporting the valve plate on said deformable member in a direction generally axially of said `barrel and supporting said deformable member on said housing.

6. In a fluid pressure energy translating device of the type having a housing, a cylinder barrel in the housing, a plurality of pistons reciprocably received in the cylinders of the barrel, and a plurality of fluid pass-ages in the barrel respectively associated with lsaid cylinders and opening outwardly of one end of the barrel; a valve plate disposed next adjacent said one end of the barrel and having a plurality of lluid passages for communication with the passages in the lbarrel, means supporting said valve plate in engagement with and in operative relation to said one end of the barrel including .a member of resiliently deformable non-metallic material extending about the barrel axis and having oppositely facing ends spaced apart in a direction generally axially of the barrel, means supporting said valve plate on the one end of said member next adjacent said one end of the barrel, and means supporting the other end of said member in fixed relation to said housing.

7. In a lluid pressure energy translating device of the type having a housing, a rotatable cylinder barrel within the housing and having a plurality of lluid passages respectively associated with the cylinders of the barrel and opening outwardly at one end thereof; a valve plate disposed next adjacent one end of said barrel and having fluid passages for communication with the passages in the cylinders of the barrel, means supporting the valve plate for limited resiliently restrained angular movement about and for limited resiliently restrained universal pivotal movement relative to the rotational axis of the barrel and urging said plate toward said one end of the barrel including a member of elastomeric material disposed adjacent t said plate and extending about the rotational axis of the barrel, said member having a pair of oppositely facing ends spaced apart generally axially of the barrel, means bonding the one end of said member next adjacent saidV plate to said plate, said member having fluid passages respectively associated with and communicating with the passages in said plate, and means bon-ded to the other end of said member and supporting said other end of the member in fixed relation to the housing.

Y8. In a fluid pressure energy translating device of the type having a housing, a cylinder barrel disposed within said housing and having a plurality fluid passages communicating at one end with the cylinders in the barrel and at the other ends opening outwardly of one end of the barrel, said other ends of the fluid passages being arranged angularly about the axis of the barrel; and annular valve plate disposed next adjacent one end of the barrel and arranged generally coaxially of the axis of the barrel, a generally annular member of elastomeric material fixed at one end to the side of the valve plate opposite said one end of the barrel and arranged concentrically of the valve plate, and means xed to the other end of said annular member for support of said annular member on the housing and fixing said other end of the an nular member relative to said housing.

9. In a fluid pressure energy translating device of the type having a housing, a cylinder barrel in said housing a plurality of piston receivable cylinders spaced angularly about the longitudinal axis of the kbarrel and extending parallel thereto, the barrel being provided with a plurality of fluid passages respectively communicating at .one end with said cylinders and at their other ends opening outwardly of one end of the barrel; a generally annular valve plate engaged with said one end of the barrel and arranged generally coaxially thereof, a generally annular support member arranged generally coaxially of said valve plate in spaced relation thereto on the side of the valve plate opposite said barrel, means fixing said support member relative to said housing, andiresiliently deformable means disposed about the axis of saidrvalve plate and extending between and fixed to said valve plate and support member, said resiliently deformable means supporting said valve plate for resiliently restrained limited movement about the axis of said barrel and for limited universal pivoting movement relative toV said axis and biasing the valve plate toward said one end of said barrel.

1). In a fluid pressure energy translating device as decribed in claim 9, said valve plate having iluid passages for communication with said other ends of the tluid passages in the barrel, said resiliently deformable means and support member having aligned tiuid passages extending therethrough and communicating with the fluid passages in said valve plate, said support member having a first portion extending radially outwardly of and circumferencially about said deformable means and having a sec-y ond portion extending radially inwardly of and circumferencially about said deformable means, said housing having a wall, said support member being supported on said wall, said wall having fluid passages communicating with the fluid passages in said support member, a plurality of fastening means engaging said first portion of said support member and spaced apart about the axis thereof and clamping said support member to said wall, and a plurality of fastening means engaged with said second portion of said support plate and spaced angularly about the axis thereof and clamping said second portion Y to said Wall; the rst mentioned fastening meansbeing sociated with said cylinders and opening outwardly of one end of the barrel; a Valve plate having fluid passages communicating with the uid passages in the barrel, and means supporting said valve plate in engagement with said one end of the barrel comprising a plurality of resiliently deformable members disposed about the axis of the valve plate in radially outwardly spaced relation thereto and iixed at one end to the valve plate and at the other end fixed relative to said axis, said deformable -f members resiliently restraining said valve plate for limited movement about the rotational axis of said barrel and for urging said valve plate toward said barrel.

12. In a fluid pressure energy translating device of the type having a cylinder barrel, a plurality of pistons respectively received in the cylinders of the barrel, and a plurality of lluid passages in the barrel respectively associated with said cylinders and opening outwardly of one end of the barrel; a valve plate having fluid passages'communicating with the iiuid passages in the barrel, means supporting said valve plate in engagement with said one end of the barrel comprising a plurality of resiliently deformable members spaced angularly about the axis of the valve plate, said deformable members being deformable in the direction of said axis, means fixing one end of each of said deformable members to the valve plate, and means fixing the other end of each of said deformable members relative to said axis, at least two of said deformable members having fluid passages respectively communicating with the fluid passages in said valve plate.

13. In a fluid pressure energy translating device of the type having a cylinder barrel, a plurality of pistons respectively received in the cylinders of the barrel, and a plurality of liuid passages in the barrel respectively associated with said cylinders and opening outwardly of one Y end of the barrel; a valve plate having fluid passages communicating with the fluid passages in the barrel,

means supporting said valve plate in engagement with said one end of the barrel comprising a plurality of metal bellows spaced angularly about the axis of the valve plate which extends parallel with the lrotational axis of resiliently restrain said valve plate for limited movement about said barrel axis and to urge said valve plate toward said barrel.

14. In a fluid pressure energy translating device of the type having a cylinder barrel, a plurality of pistons respectively received in the cylinders of the barrel, and a plurality of uid passages in the barrel respectively associated with said cylinders and opening outwardly of one end of the barrel; a valve plate having liuid passages communicating with the fluid passages in the barrel comprising a plurality of metal bellows spaced angularly about the axis of the valve plate and extending parallel to said axis, means fixing one end of each bellows to the side of the valve plate opposite said barrel, and means 10 fixing the other end of each bellows relative t0 said axis, at least two of said bellows being open at both ends and being in communication at one end with said fluid passages in said valve plate.

References Cited bythe Examiner UNITED STATES PATENTS 1,840,865 l/l932 Rayburn et al. 103-162 2,546,583 3/1951 Born 103--162 10 2,743,582 5/1956 Weidmann 103--161 MARK NEWMAN, Primary Examiner.

R. M. VARGO, Assistant Examiner. 

1. IN A FLUID PRESSURE ENERGY TRANSLATING DEVICE OF THE TYPE HAVING A ROTATABLE CYLINDER BARREL, A PLURALITY OF RECIPROCABLE PISTONS RECEIVED IN THE CYLINDERS OF THE BARREL, AND MEANS PROVIDING A PLURALITY OF FLUID PASSAGES RESPECTIVELY ASSOCIATED WITH THE CYLINDERS OF THE BARREL AND OPENING OUTWARDLY AT ONE END OF THE BARREL; A VALVE PLATE HAVING FLUID PASSAGES WHICH COMMUNICATE WITH THE PAS- 